I am planning on using a water cooled setup that I used for research a few years ago.  Four 9800GX2 Nvidia cards (8 GPUs), two quad core Opterons, two pumps, three radiators, three fans, large modified Lian Li case.  I can run it in the winter for free!  It will replace one of the 1500 watt heaters in my home that usually runs 24/7 in the cold months; same BTU's.  It will probably be winter by the time I get it all set up.  Long term, maybe some government subsidize solar panels if they have any programs going next year; a lot depends on the Bitcoin/KWH exchange rate.